Certainly it never crossed my mind that the rules about voting rings would be any different than with regular posts. HN users are passionately opposed to the voting system getting gamed; we'd have been skinned alive if we allowed it. But tptacek makes a good point about that not being obvious to everybody.
Your rules about voting rings are not public. I think that you're so used to modding the site that you forget this, but take a look at the letter of what it actually says in the FAQ.
I'm confused by your second paragraph—I just don't get it—but if there's a way to make the FAQ clearer I'd like to. There's no question that I have trouble seeing this stuff from an outside viewpoint. I'm too immersed in it.
By the way, I didn't reply to the bit about the voting rules because I think it's the only important point in your post; it isn't. It's just something that I knew how to respond to. I'm trying to write something in response to the larger substance, but am having trouble because my feelings (bad, and sad) have the better of me right now. I'll get there.
I told him when I noticed the same Twitter post that it was going to cause problems (too late!), and he was genuinely surprised.